1. Field of the Invention
The present invention relates to a cleaning device for an electrostatic photographic copying machine of the type including a sensitive drum provided at one side thereof with a paper-stripping groove, an upper blade in contact with the sensitive drum for stripping residual toner therefrom, and a lower blade in contact with the sensitive drum at a position upstream from the upper blade in the rotary direction of the sensitive drum for guiding stripped toner toward a toner withdrawing device.
2. Description of the Prior Art
Although a cleaning device which strips and withdraws residual toner from the surface of a sensitive drum by means of upper and lower blades is known, copying machines with such cleaning devices have not been provided with a paper-stripping groove provided at one or both sides of the sensitive drums. Thus, although this paper-stripping groove is important for stripping an imaged copy paper sheet from the sensitive drum by means of a stripping member extending into such groove, when the machine includes such a cleaning device this groove leads to a disadvantage that residual toner which is stripped by means of the upper blade enters the paper-stripping groove and then falls downwardly without being guided toward the toner withdrawing device by means of the lower blade. Toner which thus falls downwardly without being withdrawn leads not only to adhesion thereof to a transporting means, a driving means and the like, but also to the adhesion of such toner to the surface of copy paper sheet or to the reverse side of the following copy paper sheet through a roller, thus seriously impairing the quality of copying.
In particular, the above described disadvantages is even more remarkably produced when the upper blade periodically slides in the direction of the rotary axis of the sensitive drum in order to securely strip residual toner, since a large amount of such stripped toner then enters the paper-stripping groove.